mike wrote, on Tue, 30 Dec 2014 23:48:14 -0800:

If you don't have a vacuum gauge, you can block the hose
except for a small hole and listen to the air flow
to get some idea whether it's a leak or blockage problem.

That's interesting. I have an old vacuum gauge that I
used in the olden days to test my vehicle.

I wonder if I can adapt it for the hose.

If I understand you correctly, you're suggesting I set up
a vacuum test at each of the six wall ports. The wall port
with the least air flow would be closest to the leak.

I sure hope there isn't a leak in the walls though, as that
would be nearly impossible to find.

Do you know what *material* the pipes are in the wall?
Can they be snaked (in case it's a blockage)?